Linerless carton



Oct. 22, 1963 E. J. GRASER LINERLESS CARTON 2 Sheets-Sheet 1 Filed Jan.2, 1962 EARL J. GRA'SER By (1% ATTORNEY Oct. 22, 1963 E. ,J. LINERLESSFiled Jan. 2, 1962 2 Sheets-Sheet 2 IFIIG-B V H\\ a w We E v Q INVENTORIEARL J. GRASER BY ATTORNEY United States Patent Ofliice 3,107,837LINERLESS CARTUN Earl John Graser, Monroe, 1.21., assignor to UiinMathisson Chemical Qorporation, a corporation of Virginia Filed Jan. 2,1962, Ser. No. 163,572 3 Claims. ((11. 229-31) The present inventionrelates to linerless cartons and relates in particular to cartons ofthis class which are useful to package foodstuffs or similar materialsordinarily containing oil or greasy ingredients which tend to wick orbleed through the carton from the interior creating an unsatisfactory orsoiled appearance on the exterior of the carton.

One attempt to eliminate the tendency for oils to weep or bleed throughthe carton has been to coat at least one side of the paperboard fromwhich the carton was fabricated with a material or a coating whichrenders the paperboard impervious to fluids. Such a coating is disclosedin US. Patent No. 2,570,478 issued to Pitzl.

Another such coating is an emulsion of polyvinylidene chloride asdisclosed and claimed in a co-pending U.S. patent application S.N.757,936, now Patent No. 3,085,- 030, filed by Hendrickson et al. I

The sealed or coated side of the paperboard is turned inwardly so as tobe adjacent the material being packaged and the outside of the board isusually white coated, frequently with a thin white paper, to present aneat appearance and to form a good base for the reception of printedindicia.

The above practice has not proved entirely satisfactory because in theprocess of cutting carton blanks from paperboard material so coated, agreat amount of raw or untreated edge portions are developed in theblank which when the blank is erected into a carton present uncoatedsurfaces to oily ingredients within the package.

The result is that the oil tends to wet the uncoated edges of thepaperboard on the interior of the carton, especially at the top andbottom closures. The oil bleeds or spreads out in the interior of thepaperboard over an appreciable plane area and ultimately bleedslaterally through the board to the exterior surface creating anunsightly stain or oil mark.

The tendency for the wick action to develop along the longitudinal glueseam of the body of the carton is usually not as great as thecorresponding tendency at the top and bottom closures.

Ordinarily it is not a diflicult problem to coat the edge of the innerflap of the longitudinal glue seam disposed in the interior of thecarton because it is usually a straight, regular edge and can be coatedWhile the carton blanks are stacked in tiers prior to fabrication.

The end closures frequently involve a number of flaps, notches or slotswhich develop an irregular surface so that in this region of the cartonblank it is impractical to coat the raw edges by painting stacks ofblanks.

Accordingly, it is a principal feature of the present in vention toprovide a novel linerless carton structure.

It is a further feature to provide :a novel linerless carton structurefabricated from a single blank of paperboard.

It is a further feature of the invention to provide a linerless cartonstructure having a novel closure.

It is a further feature of the invention to provide a linerless cartonin which the entire interior thereof, including edge portions, is coatedwith a material which is impervious to fluids, such as oils and greases.

A further feature of the invention is the provision of a novellongitudinal glue seam structure for the body of a carton which operatesto prevent exposure of an uncoated edge of the glue seam to oilymaterials packaged within the carton.

A linerless carton embracing certain features of the present inventionand fabricated from a single board of paperboard having a fluidimpervious coating on one side thereof may comprise a pair of opposedsidewalls and a pair of opposed end walls hinged in series to form abox-like structure having an open top and an open bottom, saidpaperboard being turned so that said coating is disposed on the interiorof the box-like structure, return flaps hinged to opposed margins ofboth pairs of said walls, each of said return flaps being rotatedoutwardly into face-to-face contact with its mating wall to expose aperipheral margin of the coated side of said board, one of said returnflaps at the top of said box-like structure and one of said return flapsat the bottom of the structure having hinged thereto an end closureoperative to enclose the open top and bottom respectively, each said endclosure having its coated side turned inwardly when in the closedposition and each said end closure having glue flaps hinged theretooperative to overlay corresponding return flaps.

Referring now to the drawings,

FIG. 1 shows a plan view of the blank of paperboard with the imperviousside facing downwardly;

FIG. 2 is similar to FIG. 1 and shows the top and bottom closures andthe return flaps rotated inwardly into face-to-face contact with asidewall of the blank;

FIG. 3 is a sectional view of the illustration of FIG. 2, somewhatenlarged, as viewed in the plane of the line 33;

FIG. 4 shows the blank of FIG. 2 reversed with one side wall rotatedinto face-to-face contact with the main body of the blank;

FIG. 5 is a similar view showing the body of the carton fully formed;

FIG. 6 is a perspective view of the formed body of FIG. 5 showing thebody of the canton erected and the end closures rotated away from thebody of the blank;

FIG. 7 is a sectional view, somewhat enlarged, of the hinged structureutilized on the top and bottom closures;

FIG. 8 shows acompleted carton with the end closures in place; and,

FIG. 9 shows an alternative longitudinal glue seam for the body of thecarton as viewed in the section represented by the 9-9 in FIG. 6. I

Referring now to the drawings, FIG. 1 shows a paperboard blank indicatedgenerally by the letter B having a coating of polyvinylidene chloride onone side and a layer of white opaque paper on the other side.

As viewed in FIG. 1, the blank B is disposed with the white papercoating side up.

The blank includes sidewalls 111 and 12 and end walls 13 and 14 andlongitudinal glue flap 16 hinged together integrally at score lines 17,118, 1-9 and 21.

The reference numerals 22 and 23 and the hatching indicate glue margins.

The end walls 13 and 14 terminate in return flaps 26 and 27 hinged atscore lines 28 and 29.

Correspondingly, sidewalls 11 and 12 carry return flaps Stand 32 alsohinged along score lines 28 and 29.

The sidewall 11 also carries end closures for the top and bottom of thecarton identified as top closure panel 33 and bottom closure panel 34.The panels 33 land 34 carry glue flaps 36 through 39, respectively,operative to effect a closure of the carton ina manner which will becomemore apparent hereinafter.

FIG. 2 shows the first step in the erection of the carton wherein returnflaps 31 and 32 are shown rotated about score lines 28 and 29 and gluedinto face-to-face relationship with their corresponding glue margins 23and 22. The top closure panel 33 and bottom closure panel 34 are now inthe condition shown in FIG. 2.

As is apparent in FIG. 3, the bottom side of the blank,

Patented Oct. 22, 1963,

indicated by the reference numeral V, is coated with polyvinylidenechloride while the top side of the blank, indicated by the referencenumeral P, is covered with a sheet of white paper.

FIG. 4 shows the blank of FIG. 2 after two steps have been performed;namely, first the blank of FIG. 2 has been reversed so that the top andbottom panels 33 and 34 are facing downwardly (hidden) and side wall 12has been rotated about score line 19 into face-to-face contact with endwall 14 and sidewall 11.

Next glue is applied to longitudinal glue flap '16 and end wall 13, asindicated by the hatching, and end wall 13 is rotated about score line17 to establish a longitudinal glue seam thus fabricating the body ofthe carton; raw edge 40 having been coated when blank B was stacked infiat condition.

As is apparent in FIG. 5, the glue flaps 3737, integral with the top andbottom panels 33 and 34, project beyond the main body of the carton.

Referring now to FIG. 6, the body or tube of the carton is shown erectedand top closure panel 33 and bottom closure panel 34 have been rotatedabout score lines 41 and 42 (see FIG. 2) to develop a return doublereturn bend structure as is apparent in FIG. 7.

Since both panels 33 and 34 form a closure in the identical way, thedetailed description of forming the closure will be limited to the toppanel recognizing that the bottom panel is sealed to the body of thecarton in the same way.

Panel 33 is rotated towards a closed position until score line 43 (seeFIG. 2) coincides with score line 28. Continued rotation of the panel 33effects a closure of the carton and glue flaps 36, 37, 38 and 3-9 arefolded and secured to the corresponding return fiaps 2727 and 31-31bordering the top of the carton.

Note that with respect to the top and bottom of the carton, no raw oruucoated edges are exposed at the in terior of the carton because theside of the blank carrying the polyvinylidene chloride coating isinwardly disposed and a peripheral margin at the extremes of thesidewalls and end walls has been folded back exposing a band ofvinylidene chloride coated board evidenced by the glue hatching in FIG.6.

.The edges of the body of the car-ton at the top and bottom thus carry acontinuous coating which is unbroken when the respective glue flaps 2727and Lil-31. have been turned outwardly.

The longitudinal glue seam is ordinarily not bothersome; however, if itshows a tendency to wick, it may be readily coated by applyingvinylidene chloride to the edge of the blank as at 40 in FIGS. 1 and 4.

Alternatively the longitudinal glue seam of the carton may be fabricatedwith a return bend portion as indicated in FIG. 9 where the interior ofthe board marked V is coated with polyvinylidene chloride and by virtueof the return bend, indicated by the reference numeral 50, the raw edgein the longitudinal seam is turned to the outside of the carton and acontinuous coating exists throughout the full interior of the containerwith absolutely no surface available through which oily ingredient maybleed.

It is anticipated that a number of embodiments of the present inventionmay be devised without departing from the spirit and scope thereof.

What is claimed is:

1. A linerless wickproof container for packaging oily materials, saidcontainer being fabricated from a single blank of paperboard having acoating on one side thereof rendering the board impervious to oilyfluids comprising 6t a pair of opposed sidewalls and a pair of opposedend walls hinged in series to form a box-like structure having an opentop and an open bottom, said paperboard being turned so that saidcoating is disposed on the interior of the box-like structure, returnflaps hinged to opposed margins of both pairs of said walls, each ofsaid return flaps being rotated outwardly into face-to-face contact withits mating wall to expose a peripheral margin of the coated side of saidboard, one of said return flaps at the top of said box-like structureand one of said return flaps at the bottom of the structure havinghinged thereto an end closure panel operative to enclose the open topand bottom respectively, each said end closure panel having its coatedside turned inwardly when in the closed position and each said endclosure having glue flaps hinged thereto operative to overlaycorresponding return flaps. A

2. A linerless wickproof container for packaging oily materials, saidcontainer being fabricated from a single blank of paperboard having acoating on one side thereof 1 rendering the board impervious to oilyfluids comprising a pair of opposed side walls and a pair of opposed endwalls hinged in series to form a box-like structure having an open topand an open bottom, said paperboard being turned so that said coating isdisposed on the interior of the box-like structure, return flaps hingedto opposed margins of both pairs of said walls, each of said returnflaps being rotated outwardly into faoe-to-face contact with its matingWall to expose a peripheral margin of the coated side of said board, oneof said return flaps. at the top of said box-like structure and one ofsaid return flaps at the bottom of the structure having hinged theretoan end closure operative to enclose the open top and bottomrespectively, each said end closure having its coated side turnedinwardly when in the closed posi tion and each said end closure havingglue flaps hinged thereto operative to overlay corresponding returnflaps, said container having a longitudinal glue seam formed with areturn bend portion so as to dispose the edge of the seam to theexterior of the container.

3. A linerless wickproof container for packaging oily materials, saidcontainer being fabricated from a single blank of paperboard having acoating of polyvinylidene chloride on one side thereof rendering theboard impervious to oily fluids comprising a pair of opposed sidewallsand a pair of opposed end walls hinged in series to form a box-likestructure having an open top and an open bottom, said paperboard beingturned so that said coating is disposed on the interior of the box-likestructure, return flaps hinged to opposed margins of both pairs of saidwalls, each of said return flaps being rotated outwardly intoface-to-face contact with its mating wall to expose a peripheral marginof the coated side of said board, one of said return flaps at the top ofsaid box-like structure and one of said return flaps at the bottom ofthe structure having hinged thereto an end closure operative to enclosethe open top and bottom respectively, each said end closure having itscoated side turned inwardly when in the closed position and each saidend closure having glue flaps hinged thereto operative to overlaycorresponding return flaps.

References Cited in the file of this patent UNITED STATES PATENTS1,041,504 Moore Oct. 15, 1912 1,351,278 Billstein Aug. 31, 19202,409,460 Waters Oct. 15, 1946 2,474,523 Guyer June 28, 1949 2,979,247Pellaton et a1. Apr. 11, 1961

1. A LINERLESS WICKPROOF CONTAINER FOR PACKAGING OILY MATERIALS, SAIDCONTAINER BEING FABRICATED FROM A SINGLE BLANK OF PAPERBOARD HAVING ACOATING ON ONE SIDE THEREOF RENDERING THE BOARD IMPERVIOUS TO OILYFLUIDS COMPRISING A PAIR OF OPPOSED SIDEWALLS AND A PAIR OF OPPOSED ENDWALLS HINGED IN SERIES TO FORM A BOX-LIKE STRUCTURE HAVING AN OPEN TOPAND AN OPEN BOTTOM, SAID PAPERBOARD BEING TURNED SO THAT SAID COATING ISDISPOSED ON THE INTERIOR OF THE BOX-LIKE STRUCTURE, RETURN FLAPS HINGEDTO OPPOSED MARGINS OF BOTH PAIRS OF SAID WALLS, EACH OF SAID RETURNFLAPS BEING ROTATED OUTWARDLY INTO FACE-TO-FACE CONTACT WITH ITS MATINGWALL TO EXPOSE A PERIPHERAL MARGIN OF THE COATED SIDE OF SAID BOARD, ONEOF SAID RETURN FLAPS AT THE TOP OF SAID BOX-LIKE STRUCTURE AND ONE OFSAID RETURN FLAPS AT THE BOTTOM OF THE STRUCTURE HAVING HINGED THERETOAN END CLOSURE PANEL OPERATIVE TO ENCLOSE THE OPEN TOP AND BOTTOMRESPECTIVELY, EACH SAID END CLOSURE PANEL HAVING ITS COATED SIDE TURNEDINWARDLY WHEN IN THE CLOSED POSITION AND EACH SAID END CLOSURE HAVINGGLUE FLAPS HINGED THERETO OPERATIVE TO OVERLAY CORRESPONDING RETURNFLAPS.